What does 'See bright light' mean?

Why is bright light important and how do I do?

Written by Jacob Ravn Updated over a week ago

What we mean when we ask you to 'See bright light'

Prioritize exposure to as much bright light as possible. The best source of bright light is sunlight, so if the timing is right, get outside and don’t wear sunglasses! Indoor light will also work so turn on all the lights if you can and try to find blue-enriched, cool-looking white light.

When flying:Raise the window shade if it’s light outside, turn on the overhead light, and turn on the TV or use your laptop or tablet.

If you can’t get continuous bright light exposure, try to get at least 15 minutes of exposure every hour - even short, intermittent light exposure will help.

Why do I need to expose myself to bright light?

Light is the key to beating jet lag. Light has the most powerful influence on circadian rhythms and seeing light at the right time is the most important factor in the plan. The effects of light vary by time of day, and the plan lets you know when the light has its more powerful benefits and when you should prioritize light exposure.

What will happen to my jet lag if I don’t see bright light at this time?

All visible light can affect the circadian rhythm so when asked to see bright light, any light exposure is better than none. Do what you can to maximize your exposure. If you are unable to prioritize light at this time, however, it will slow down the adaptation of your body clock and may make your jet lag last a little longer. Do your best – it’s really important to the plan.

The science

Light is the most important factor in resetting your circadian rhythm — the disruption of the light-dark cycle is in fact what causes jet lag in the first place. Light resets our circadian rhythm to 24 hours each and every day, and is detected by special photoreceptors in the eye.

Light can shift the clock earlier (called an advance) or later (called a delay) depending on the timing of light. This relationship is described by a “phase response curve”. Generally speaking, light exposure in the evening or early night will delay the clock, and light in the late night or early morning will advance the clock. Timeshifter uses this property of light to time the light exposure advice and ensure that you adapt as quickly as possible to new time zones.